Having been in a gloriously burning building, I can attest to the following:

1) you have less time than you think
2) do NOT get between me and the nearest safe exit. I can become that "irresistible force" that one often hears about.

One night in a hotel, I was watching a Discovery Channel show about travel hazards. One was about hotel fires. The host stated that on average one has 90 seconds from the time they hear the alarm and smell smoke to get to the street. THAT NIGHT, the alarm went off, and there was smoke in the hallway once I exited the room.

90 seconds is generous.....